Apparatus for automating the serving of customer-dialed station paid coin calls



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Q @Dx N. R. SHAER July 1,- 1969 APPARATUS FOR AUTOMATING THE SERVING OF CUSTOMER-DALED sTATIoNfPAID COIN CALLS Sheet Filed June 6, 1966 United States Patent O U.S. Cl. 179-71 15 Claims ABSTRACT OF THE DISCLOSURE A system is disclosed for serving station-to-station customer dialed coin calls on a wholly automatic basis without any operator intervention being required either for notifying the calling party of the monetary deposits required or for monitoring the collection of the required charges. A system controller is provided for deriving call charge' information and for controlling an announcement apparatus which transmits the derived charge information to the calling station. The tones generated at the calling station as coin deposits are made are detected by a special receiver and transmitted to the system controller which then determines whether the amount deposited corresponds to that requested by the announcement apparatus.

This invention relates to a switching system, and more particularly to a switching system having improved facilities for serving customer-dialed toll calls originating at coin pay stations. This invention further relates to a switching system in which equipment is provided for automatically performing the functions that heretofore required operator intervention on customer-dialed stationto-station coin toll calls. This invention still further relates to a telephone system which, during the serving of calls of the foregoing type, automatically transmits an announcement containing time and charge information to a calling coin station, monitors the coins deposited by the calling party, and determines whether the amount deposited equals the amount requested in the announcement.

Recent improvements in the iield of telephone switching permit an increasing percentage of toll calls to be completed on a customer-dialed basis. These improvements permit customer-dialed calls to be served, depending on their type', either without any operator assistance whatsoever, or with a substantial reduction in the quantity of operator assistance compared with that heretofore required. For example, a substantial percentage of all customerdialed noncoin station-to-station toll calls may now be completed without operator assistance. Also, the recently introduced person-to-person type systems permit calls Such as person-to-person, collect, charge-to-third party, etc., to be completed on a customer-dialed basis from noncoin stations with operator assistance being required only for the furnishing of the service required above and beyond the completion of a connection to the called station.

The copending L. I. Cerny et al. application, Ser. No. 325,842, filed Nov. 26, 1963, now Patent 3,341,662, issued Sept. 12, 1967, and the R. J. Jaeger, Ir. et al application, Ser. No. 519,787, filed Ian. 10, 1966, disclose equipment which permits both station-to-station and person-toperson type calls originating at coin pay stations to be served on a customer-dialed basis. In accordance with the systems disclosed in each of these applications, operator assistance is required on station-to-station coin calls for the purpose of transmitting time and charge information to the calling party and for monitoring the deposit of the requested charges. The time and charge information relayed by the operator is automatically derived by a system controller and displayed at the operators position. On person-to-person type coin calls, operator assistance is required for the same reason as on the station-to-station type, as well as for additionally providing the services required above and beyond the completion of a connection to the called station.

The operator assistance provided on person-to-person calls is of such a varied personal and specialized nature that, at the present state of the art, it cannot be readily automated. On the other hand, the services performed by the operator on station-to-station coin calls are, for the most part, routine, since her sole function on these is (l) to relay to theI calling station the time and charge information that has been automatically derived and displayed at her position and (2) to monitor the collection of the requested charges from the tones generated at the calling coin station in response to each coin deposit.

A large percentage of all customer-dialed toll calls originating at coin stations are of the station-to-station type and, thus, the elimination of the need for operator intervention on these would be most desirable in terms of economies of operation and improved customer service. Operator assistance would then be required on only a relatively small percentage of coin toll calls, i.e., those of the person-to-person type.

Itis therefore an object of the invention to provide improved facilities for serving customer-dialed station-tostation coin toll calls.

It is a further object to provide facilities which permitr customer-dialed station-to-station coin toll calls to be completed without operator intervention.

It is a further object of the invention to automate the serving of calls of the foregoing type by the provision of equipment which performs the call-serving functions that heretofore' required operator intervention.

In accordance with the specific disclosed illustrative embodiment of the invention, equipment is provided which permits customer-dialed station-to-station coin toll calls to be completed without operator intervention. This equipment comprises (l) recorded announcement apparatus which automatically transmits time and charge information to a calling coin station, and (2) apparatus which utilizes the tones generated at the calling station in response to each coin deposit to determine Whether the amount deposited matches the amount requested. The announcement and the coin deposit monitoring equipment may be utilized at the beginning of a call for the collection of the initial period deposit, at the beginning of each overtime period for the collection of interim overtime charges and, upon the termination of a call for the collection of postpay overtime charges.

The invention is shown embodied in a system of the type disclosed in the aforementioned Jaeger-Joel specilication. Jaeger and Joel disclose equipment which provides various types of call service on calls incoming to a toll oiice from the local oiiices it serves on an originating basis. The Jaeger-Joel system is not a switching system, per se; it does not comprise a portion of either the toll or local offices; and it is situated intermediate the toll oiiice and the local offices. The Jaeger-Joel equipment is typically referred to as a traffic Iservice position system (TSPS) since it is independent both geographically and equipmentwise of any existing oiice and since its sole function is to provide call service on many types of calls incoming to the toll office. The TSPS center is designated in this manner, rather than as a switching system, since it performs no switching operations whatsoever in connection With the selection of a route or trunk that is to fbe utilized in extending a call from a local to a toll oce.

The equipment provided at the TSPS center includes operator positions, change data recording apparatus, call-timing facilities, together with apparatus for temporarily connecting operator positions to calls requiring assistance for their completion. Each call extended via the TSPS center to a toll office is monitored and timed and, if desired, pertinent charge data therefor is recorded upon the call termination. If the call requires operator assistance, a connection within the TSPS center to an operator is established at the same time the forward connection is being set up by the toll oflice. Once connected, the operator performs the call duties required of her and then depresses keys at her position to indicate the type of service provided and to release her position from the connection. This leaves the calling and called stations connected, speechwise, for the call duration.

The installation of the Jaeger-Joel TSPS equipment in an existing telephone network enables it to serve many additional types of calls with little or no modifications being required at either the local or toll oflices. Included in the types of calls that may be then served by the resultant system, once the TSPS center is incorporated as a part thereof, are :(1) noncoin customer-dialed person-toperson type calls for which the TSPS center provides the operator assistance required above and beyond the completion of the connection to the called station, (2) noncoin customer-dialed station-to-station toll calls for which the TSPS center performs a timing and charge data recording operation, (3) customer-dialed station-to-station coin toll calls for which the TSPS equipment derives the applicable time and charge information and transmits it to an operator (the operator, in turn, orally relays the information to the called station and monitors the collection of the required charges), and (4) customer-dialed coin persons-to-person type calls which are served in the same manner as coin station-to-station calls except that, in addition, the operator must provide the service required on noncoin person-to-person type calls.

The equipment provided in accordance with my invention at the TSPS center includes recorded announcement apparatus comprising, for example, a plurality of magnetic tape mechanisms, a plurality of separate tracks on a magnetic drum, or any other suitable apparatus by means of which dierent recorded announcements may be made available upon selection for transmission back to a calling station. In accordance with a first alternative embodiment of the announcement apparatus, each track may contain an entire message representing a unique combination of time and charge parameters. The announcements on the plurality of tracks together are capable of providing time and charge information for any call served by the TSPS center. The announcement apparatus may alternatively comprise a plurality of recorded tracks, each of which contains an elemental portion of a message. Each message transmitted to a calling station is synthesized by connecting the call to a plurality of tracks sequentially in a required timed relationship.

Upon the arrival of a coin station-to-station toll call at a TSPS center equipped in accordance with my invention, called and calling station information is received from the local office and registered in the TSPS system controller as disclosed by Jaeger-Joel. The initial period time and charges are derived by the controller in response to the registration of the calling and called station information as well as in response to information available within the TSPS system itself, lsuch as for example, the time of day, etc. After this information is derived, a temporary connection at the TSPS center is established between the incoming call and the announcement apparatus. The controller then controls the operation of the announcement apparatus so that it transmits a message to the calling party advising him of the applicable initial period time and charges, such as for example, 60 cents for three minutes.

It is known in the art to equip coin stations with coin collection apparatus which emits audible signals signifying the amount of coins deposited. In particular, coin collection apparatus has recently been introduced which has only a single slot for the acceptance of all coins, with the deposit of each type of coin causing a series of tone pulses to be generated. The number of pulses generated for each coin deposit is equal to the number of nickels in the deposit, i.e., one pulse for 5 cents, two pulses for 10 cents, and five pulses for 25 cents. Patents which disclose coin collection apparatus of this type are 3,146,312 to E. R. Andregg, et al. of Aug. 25, 1964; 3,170,039 t0 E. R. Andregg, et al. 0f Feb. 16, 1965; 3,- 116,370 to E. R. Andregg, et al. of Dec. 31, 1963.

The equipment I provide at the TSPS center further includes a coin tone receiver which detects the tones generated by the calling station in order that the system controller may determine Whether the amount deposited matches that requested in the recorded announcement. Following the transmission of the recorded announcement to the calling station, the TSPS switching network disconnects the call from the announcement apparatus and connects it to an idle coin tone receiver. The receiver detects the coin tones generated at the calling station and transmits signals to the System controller signifying the receipt of each coin tone pulse. The system controller counts the coin pulses and determines whether the calling party has deposited the requested initial period charge.

If the amount deposited by the calling party is either less or more than the amount requested, the call is routed to an available operator position where it is served in the manner described in the Jaeger-Joel specification. If the amount-deposited equals the amount requested, the coin tone receiver is disconnected and the system controller effects the remaining operations required on the call at the TSPS center. As described in Jaeger-Joel, these include the connection of the call to an outpulser which transmits to the toll office the information it requires for the extension of the connection to the terminating oice and called station. The outpulser is then disconnected and the parties may converse after the called station answers.

Each call is automatically timed by the system controller. If the call now being described is terminated before the initial period elapses, the appropriate data for the call is recorded and the TSPS circuits serving the call are restored to an idle condition, as disclosed by Jaeger-Joel. Two different procedures are commonly utilized to collect the overtime charges for those coin calls which extend into overtime. In accordance with one procedure, the charges are collected on an advance basis at the beginning of each overtime interval. With the second procedure, the charges are collected on a postpay basis at the termination of the call.

If the first overtime collection procedure is utilized, the system controller (l) detects the termination of the initial period, (2) derives the time and charge for a single overtime period, (3) connects the call to the announcement equipment, (4) controls the operation of the announcement equipment so that it transmits a message signifying the duration of the overtime period and the amount of charge that must be deposited at this time, (5) disconnects the call from the announcement apparatus and (6) connects it to a coin tone receiver which monitors the collection of the requested charge and transmits an indication thereof to the system controller. The coin tone receiver is subsequently disconnected if the calling party deposits the requested amount, and the parties are then free to converse for the duration of the overtime period. If the deposit is less or more than the requested amount, the call is connected to an operator position. This collection procedure is repeated at the beginning of each subsequent overtime interval for the duration of the call.

If the second procedure is used (the collection of overtime charges on a postpay basis), the system controller, upon the termination of the initial period, connects the call to the announcement equipment which (1) informs the calling station that the initial period has ended and that the call is entering overtime, (2) advises the calling party of the charge and duration of a single overtime period, and (3) requests that he ilash his switch hook upon the termination of the call. The announcement apparatus is then disconnected and the overtime portion of the call is timed by the system controller. Upon the call termination, the system cont-roller (1) computes the chargeable overtime and the overtime charges, (2) connects the call to the announcement equipment, (3) disconnects the announcemen equipment after the required announcement has been generated and transmitted to the calling station, and (4) connects the call to a coin tone receiver which monitors the collection of the requested overtime charges in a manner similar to that already described for the collection o f initial period charges.

It may be seen from the foregoing that my invention eliminates the necessity of operator service on most station-to-station coin DDD calls and thereby contributes to improved operating efficiencies and improved customer call service.

A feature of the invention is the provision of announcement apparatus which, in response to the receipt of calling and called station information on customer-dialed coin calls, automatically transmits to the calling station an announcement containing time and charge information including the monetary amount that is to be deposited as call charges.

A further feature of the invention is the provision of equipment for automatically determining Whether the amount deposited at the calling station matches that requested in the announcement.

A further feature is the provision of equipment responsive to a determination that the proper amount was deposited at the calling station for controlling the completion of a connection to the called station.

A still further feature is the provision of equipment for monitoring and timing the call following an olf-hook condition at the called station and for automatically transmitting an announcement to the calling station upon the call termination indicating additional time and charge information pertaining to that portion of the call extending beyond the period for which the charges were initially paid.

It is another feature to provide in a call service center, located intermediate a toll and a local oice, equiplment which is responsive to the receipt of calling and called station information on customer-dialed coin calls for deriving initial period time and charge information, vequipment which automatically transmits an announcernent containing this information to the calling station, equipment which monitors coin deposit signals generated at the calling station in response to coin deposits thereat, equipment which is responsive to the coin deposit signals for determining whether the amount deposited at the calling station matches that requested in the announcement, 'and equipment which controls the completion of a connection through the toll oflice to the called station in the event thatV the proper amount is deposited at the calling station.

It is still another feature to provide in the call service center equipment for monitoring and timing the call following the off-hook condition at the called station, equipment effective upon an on-hook condition at either the called or calling station for determining the total charge for the call, and equipment operative in the event that additional charges are due beyond those already deposited for automatically transmitting an announcement to the calling station indicating additional time and charge information, including the additional charges due.

These and other objectives, advantages, and features of the invention may be more readily understood upon a reading of the following description of an exemplary illustrative embodiment thereof taken in conjunction with the drawing in which:

FIG. 1 discloses a block diagram embodiment of the invention;

FIGS. 2A, 2B, and 2C, when arranged as shown in FIG. 3, diagrammatically disclose additional details of the invention; v

FIGS. 4 and 5 disclose an MF trunk circuit;

FIGS. 6 and 7, when arranged as shown in FIG. 8, disclose a coin control trunk circuit;

FIG. 9 discloses a coin tone receiver;

FIGS. 10, ll, and 12A through 12D, rwhen arranged as shown in FIG. 13, disclose a stored program controller (SPC); and

FIGS 14 and 15 disclose two separate embodiments of my announcement apparatus.

Block diagram-FI G. 1

FIG. l diagrammatically discloses my invention in a manner which facilitates an understanding of its broader aspects. The invention is shown as embodied in the system disclosed in the aforementioned Jaeger-Joel specification, which is hereby incorporated as part of the present application to the same extent as if fully disclosed herein. Shown on FIG. 1 is a TSPS center 100` which is interconnected between the local oces 101A and 101B and toll oiice 102. The TSPS center contains a plurality of trunk circuits 1031 through 10S-n, each of which is connected on its incoming side to a corresponding one of local oce outgoing trunk circuits 120A-1 through 120E-n and on its outgoing side to a corresponding one of toll oflice incoming trunk circuits 121-1 through 121-11. With this arrangement, each outgoing trunk circuit at the local oflice is individual to a different one of the TSPS trunk circuits 103- and, in turn, to a diierent one of the toll- 104, which is connected on its left side to trunk circuits 103- and on its right side to various other circuits, such as for example, outpulsers 106, digit receivers 107, position buffers 108-, coin tone receivers 150, announcernent equipment 152, and miscellaneous other circuits which, for the purpose of this figure, are represented generally as miscellaneous tone and service circuits 117. Switching network 104 includes link 104A, which contains the circuit paths required to interconnect the circuits having left side network appearances with those having appearances on the right side of the network. The network 104 further includes network controller 104B, which controls the operation of the link in its path-establishing function.

TSPS further includes a system controller (system control 105), which is connected by cable 113 to trunk circuits 103; by cable 116 to controller 104B; by cable to recorder 114; by cable 111 to outpulsers 106, digit receivers 107,'and service circuits 117; by cable 112 to position buffers 108; by cable 122 to positions 109-, and by cable 128 to the coin tone receivers and the announcement equipment 152. These connections permit the system control to regulate, control, and coordinate the operation of each circuit in order that the TSPS center may furnish the service required of it on each call.

Each TSPS trunk circuit 103- is connected by means of two separate conductor pairs to two separate link appearances on the left side of link 104A. Conductor pair T and R connects the incoming side of the trunk circuit to the link. This permits the circuits on the right side of the link to communicate with the local olice. The T1 and R1 conductor pair connects the outgoing end of the trunk circuit to the left side of the link. This permits the circuits on the right side of the link, such as for example, outpulsers, to communicate with the toll oice.

Digit receivers 107 receive call information outpulsed from a local office on each call served by the TSPS center. These receivers may be of diiferent types, such as for example, DP or MF, depending upon the mode of outpulsing utilized. Outpulsers 106, which advantageously may be of the MF type, transmit to the toll oliice the information it needs on each call. AMA recorder 114 records pertinent charge data upon the termination of a call in respo-nse to information received from system control 105.

The TSPS center functions to extend a connection from a calling local oflice outgoing trunk circuit to its related toll oice incoming trunk circuit via the TSPS trunk circuit 103- common to the local and toll oflice trunk circuits. The TSPS center furnishes the call services required of it simultaneously with the extension of the connection to the toll office. This service may include the recording of call charge data by recorder 114. This service may further include the attachment of an operator position 109- to the calling TSPS trunk circuit, via the link, if operator assistance or intervention is required for any reason. The operator position is disconnected from the call when the required assistance has been furnished. The calling and called stations ramain connected via the TSPS trunk circuit for the call duration. The system control monitors and times the call and, upon its termination, causes recorder 114 to perform a charge data recording operation.

In order to illustrate the operation of my invention as shown on FIG. 1, let it be assumed that a customer-dialed coin call of the station-to-station type originates at coin station 119 served by local office 101A. Let it further be assumed that this call requires a routing to toll office 102 via the TSPS center. Finally, let it be assumed that in serving this call, local oice 101A selects outgoing trunk circuit 120A-1. The seizure of this outgoing trunk circuit generates a signal which is received by TSPS trunk circuit 103-1 and transmitted to system control 105 over cable 113. System control responds and commands controller 104B to establish a network connection between the T and R conductors of trunk circuit 103-1 and digit receiver 107. The digit receiver receives the calling and called oice information outpulsed from the local ollice and transmits it to system control over cable 111. System control signals controller 104B to break down the connection to the receiver when the local ollice outpulsing has been completed.

System control determines that the call is of the customer-dialed coin station-to-station type from the received call information and devices time and charge information applicable to the call, including the duration and charge for the initial period. The announcement equipment contains the facilities required for providing recorded time and charge information for any call served by the TSPS center. As already mentioned, this equipment may cornprise either a plurality of recorder tracks, each of which contains the entirety of a message, or alternatively, it may comprise announcement tracks containing less than a complete message per track together with equipment for synthesizing any message by connecting a call to a plurality of tracks sequentially in a required timed relationship. The announcement equipment is connected over conductors 153-1 through 15S-n to right side link appearances.

After system control 105 derives the initial period time and charge information, it causes the T and R conductors of trunk circuit 10.3-1 to be connected via the network to the announcement equipment. The operation of this equipment is controlled, by signals transmitted over cable 128, so that the required message is transmitted via the switching network trunk circuit 103-1 and local office 101A back to the called customer coin station 119. This message might, for example, request the calling party to deposit 60 cents for three minutes.

The network controller disconnects the T and R conductors of trunk circuit 103-1 from the announcement equipment following the transmission of the selected message to the calling station. It then connects these conductors to an idle coin tone receiver 150. The coin tone receiver 125 comprises frequency selective circuits and detectors which provide an output signal in response to the reception of each coin tone pulse. Following its connection to the TSPS trunk circuit, the coin tone receiver detects each tone pulse received from the calling station and transmits an indication of the reception of each pulse to system control. System control registers and counts the pulse indications and determines whether the amount deoosited matches the initial period charge the calling party was requested to deposit. If the amount deposited matches that requested, the call is completed as subsequently described. lf the amount deposited is greater or less than the requested amount, the T and R conductors of the TSPS trunk circuit are connected to a right-hand network appearance of an idle operator position 109- over cable 110-. The remainder of the call is then served in the manner disclosed in the Jaeger-Joel specification.

At the same time the announcement equipment and coin tone receivers are being utilized in connection with the initial period deposit collection, system control proceeds with the completion of the forward connection by causing the network controller to establish a network connection between outpulser 106 and the T1 and R1 conductors of trunk circuit 103-1. Once this connection is established, the outpulser transmits call information forward to the toll office which, in turn, controls the establishment of the forward connection to the terminating oice in the normal manner. The outpulser is disconnected by the link from the calling connection upon the termination of outpulsing. The timing of the outpulsing operation is controlled so that the operations within the TSPS center associated with the collection of the initial period charges are completed by the time the ringing of the calling station takes place. At this time, assuming the proper charges are deposited, all of the priorly established link connections between the T and R and the T1 and R1 conductors of trunk circuit 103-1 will have been broken down. The calling and called stations remain interconnected by the TSPS trunk circuit at this time for the duration of the call. System control monitors and times the call by means ot its interconnections 113 with trunk circuit 103-1.

It has been assumed that the initial period duration applicable to this call is three minutes. Therefore, at the end of three minutes, system control causes the link to interconnect the T and R conductors of trunk circuit 103-1 with the announcement equipment, which informs the calling party that the initial period has elapsed and that the call is now entering overtime. Also, in the same manner as is current practice for operators in most areas, the announcement requests the calling party to ash his switch hook upon the termination of the call. The link disconnects the announcement equipment from the call on the conclusion of this message and the call is then timed and monitored for the duration by system control.

The termination of the call is detected by system control, which then (1) computes the chargeable overtime, (2) computes the overtime charges due, (3) selects the announcement track or tracks containing the message applicable to the computed overtime duration and charges, (4) connects the T and R conductors of trunk circuit 103-1 to this selected track or tracks, (5) controls the operation of the announcement equipment so that the required message on the selected track is conveyed to the calling station, (6) disconnects the trunk from the announcement equipment and connects it to a coin tone receiver, and (7) counts the coin tone pulses received by the coin tone receiver to determine that the required overtime charges are deposited. The TSPS trunk circuit is then disconnected from the coin tone receiver and restored to an idle condition for the serving of another call.

The preceding description assumed that the overtime charges were collected on a postpay basis. The operation of the call was described in this manner since this is the method by which the overtime charges for coin toll calls Detailed description-FIGS. 2A through FIGS. 2D

FIGS. 2A through 2C, when arranged as shown in' FIG. 3, disclose additional details of the embodiment of the invention shown on FIG. 1'. Each element on FIGS.

2 corresponding to an element on FIG. 1 is designated in a manner to indicate the correspondence. Thus, local oice 201A on FIG. 3 corresponds to local oice'101 on FIG. 1, etc. Whenever such a one-for-one correspondenceis possible, each such element on FIGS. 2 also has, inside the rectangle representing the element, parentheses enclosing the numerical designation of the corresponding element on FIG. 1. However, a one-for-one correspondence between each element on FIGS. 2 and FIG. 1

is notvalways poss-ible, since FIGS. 2' are vconsiderably more detailed and contains many elements which are not Separately shown on FIG. 1.

The embodiment of FIGS. 2 is similar to that of FIG.

1, vin that it discloses a local oice 201A having an l outgoing trunk circuit 220A extending via TSPS trunk circuit 203 to an incoming trunk circuit 221 and a toll office 202. Only one such interconnection between ajlocal and a toll oice is shown in order to minimize 'thevcomplexity ofthe drawing and to facilitate an understanding of the invention. Network 204-comprises a two-stage network having a trunk link 204A and a position link 204B, together with link controllers 204C and 204D. The two links together function to interconnect TSPS trunk circuits having trunk link appearances With thev-.service'circuits having appearances on the right side of the position 1ink.,The service circuits are shown in greater detail than on FIG. l and comprise outpulsers 206,?digit receivers 207, coin control trunk circuits 246, tone circuits 243, operator cut-through circuits 224-, service circuits 244, coin tone lreceivers 250, and the announcement apparatus 252. The digit receivers, the outpulsers, the service circuits, the tone circuits, and the coin cont-rol trunk circuit, the coin tone receiver, and the announcementapparatus perform the same functions already described 1n scanners 236, group gate 235, and position signal distributor 240. The embodiment of the invention shown on FIGS. 2, as well as on other drawing figures, comprises an electronic stored program controlled system which utilizes many circuits similar to those shown in detail in the copending application to A. H. Doblmaier et al., Ser. No. 334,875, iled Dec. 31, 1963. Doblmaier et al. discloses an electronic type local ot'ice which is controlled in its operation by a real time stored program processor. The Doblmaier et al. system is also disclosed in detail in the entirety ofthe September 1964 issue of the Bell System Technical Journal. Although the invention does not comprise a switching center in the sense that a call-routing operation is performed, it makes extensive use of circuits of the type shown in Doblmaier et al.

rI he SPC may be considered to be the brain or basic control-ling mechanism for the entire TSPS center. It comprises a stored program real time machine having a processor 230A and a memory 230B. The processor performs arithmetical and logical operations on the data it receives from the memory,-as well as on the data it receives from circuits external to the SPC, such as for example, from the scanners. The memory comprises bulk memory, which is supplied in suicient quantity to store all the temporary and -semipermanent information and data required for the operation of the TSPS center. As described in Doblmaier et al., as well as in Jaeger-Joel, the SPC, in performing its functions, receives signals from memory and from the scanners, performs the necessary arithmetical and logical operations in response to the received signals, and generates output commands which are transmitted to other circuits to control them in the performance of their required call functions. The circuits which respond to the SPC output commands are referred to as peripheral circuits since they are peripheral,

connection with FIG. 1. The operator cut-through circuits are rudimentary trunk circuits Whose function is to interconnect the talking circuits of each operator position with an appearance on the position link. The operatorpositions are shown on the -right side of FIG. 2C vand are designated 208-2 through 209-63'. Each positionfcircuit f is individually associated with one of the position buffer circuits 208-2 through 208-63. Eachoperator position is also individually connected tto'one of the-operator cutthrough circuits 224-2 through 224-63, each of which on its left sideextends to an individual position link appearance. The details ofthe equipment provided in each operator position, together with the manner in which. each functions during the serving of the various types of calls that may be extended to a position is described in detail in the Jaeger-Joel` specification, to which reference is made for an understanding of these details.

System control 105 on FIG. 1 is not shown as such on FIGS. 2 since it represents many circuits which are individually shown on FIGS. 2 and which together cooperate to control the operation of the system. These circuits on FIGS. 2 include stored program control 230, hereinafter referred to as SPC, communications bus translator (CBT) 231, central pulse distributor (CPD) 232, signal distributor 233, .trunk scanners 234, master or external, to the SPC.

The SPC communicates with the peripheral circuits by means of communication paths referred to in this speciiication as buses On FIG. 2, the buses which transmit the SPC commands to the various peripheral circuits are the 1-out-of-N address bus 239 and the binary address bus 238. The SPC transmits its output commands in binary form directly to the CBT over conductor paths 247 and 248. The CBT applies the SPC binary information to the binary address bus system. The CBT also translates the SPC binary output into a plurality of l-out-of-N information bits and applies these to the 1-out-of-N address bus system. Thus, for each binary command received, the CBT applies a corresponding binary command to the binary address bus and, in turn, to the peripheral circuits served by this bus. Simultaneously, a A1outofN type command is applied to the 1out-of-N address bus and to the peripheral circuits it serves.

Each command transmitted from the SPC via the CBT to the address bus system functionally represents or indicates a task that is to be performed by a peripheral circuit. Each address bus system comprises a plurality of wires, most of lwhich are connected to a plurality of peripheral circuits in common. Thus, a command applied by the CBT to a combination of address bus conductors is transmitted to all peripheral circuits to which this combination of conductors is connected. In the normal course of events, only one peripheral circuit responds to a command, even though many peripheral circuits receive it.

The input portion of each peripheral circuit is arranged so that it does not respond to an address bus command unless it has iirst been primed or unlocked by the reception of a special signal hereinafter termed an enable pulse. The central pulse distributor operating under control of the SPC is the circuit which transmits enable pulses to the peripheral circuits. These pulses are transmitted over dedicated conductor pairs unique to each peripheral circuit. The SPC effects the operation of a selected peripheral circuit by causing the CBT to gate 

